Thiophene base colorants useful for coloring thermoset resins

ABSTRACT

Thiophene based colorants useful for coloring thermoset resins such as polyurethanes being the formula; ##STR1## wherein R 1 , R 2  and R 3  are selected from halogen, carboxylic acid, alkanoyl, aryloyl, carbocyclic forming polymethylene chains, alkyl, aryl, cyano, thioalkyl, dithioalkyl, thioaryl, dithioaryl, thiocyano, carboxyalkyl, carboxyaryl, amidoalkyl, amidodialkyl, amidoaryl, amidodiaryl, oxyalkyl, thioamidoalkyl, thioamidodialkyl, or hydrogen when an adjacent group is isobutyryl; R 4 , R 5 , and R 7  are selected from hydrogen alkyl, oxyalkyl, sulfonamidoalkyl, sulfonamidoaryl, amidoalkyl, amidodialkyl, amidoaryl, amidodiaryl, halogen, thioalkyl and thioaryl; and R 8  and R 9  are selected from polyalkylene oxide, copolymers of polyalkylene oxides, and hydroxyalkylenes.

This is a continuation application of co-pending Ser. No. 058,696, filedJune 1, 1987, now U.S. Pat. No. 4,775,768 which is in turn acontinuation of U.S. Ser. No. 624,379, filed June 25, 1984, nowabandoned.

This invention relates to novel reactive colorants based on thiophenederivatives which have particular application in coloration of thermosetresins, exemplified by polyurethanes.

It is known that polyurethane resins, produced by the reaction of polyoland an isocyanate may be colored by adding a pigment or dyestuff to theresin. When, however, certain thermoset materials such as polyurethanesare colored with a pigment, the resulting product may be only slightlytinted at normal pigment concentrations, and may thus require larger,undesirable amounts of pigment if a dark hue is to be attained. Thisphenomenon is particularly apparent in the case of polyurethane foams.On the other hand, if a conventional dyestuff is employed to color thethermoset product, water resistance, oil resistance, and/or resistanceto migration of the dyestuff may often be disadvantageously inadequate.When such a dye is used as a coloring agent, it is difficult to preventbleeding of the dye from the colored resin product. Thermosetting resinproducts, such as polyurethanes, however, which have been colored with adyestuff, have certain advantages. Particularly, such colored productsmay, for instance, possess a clearer hue, and improved transparencycharacteristics, both of which are important commercial attributes.

Dyes rather than pigments are preferred for use in coloring polyurethaneresins because each molecule of a dye imparts color to the product.Conversely, only the surface molecules of pigment particles impartcolor. From the standpoint of utilization, then, dyes are more effectivethan pigments. Due to the above noted shortcomings of dyes, however,pigments have historically been used extensively.

One definite improvement in prior art techniques is set forth incommonly assigned U.S. Patent 4,284,729 to Cross et al in which a liquidpolymeric colorant is added to the reaction mixture during production ofa thermoset resin. Cross et al determined that a liquid, reactive,polymeric colorant could be added before or during the polyadditionreaction to achieve desired coloration of the thermoset resin. Thespecific polymeric colorant of Cross et al has the formula:

    R (polymeric constituent-X).sub.n

wherein R is an organic dyestuff radical; the polymeric constituent isselected from polyalkylene oxides and copolymers of polyalkylene oxidesin which the alkylene moiety of the polymeric constituent contains 2 ormore carbon atoms and such polymeric constituent has a molecular weightof from about 44 to about 1500; X is selected from --OH, --NH₂ and --SH,and n is an integer of from about 1 to about 6. The liquid coloringagent is added to the reaction mixture in an amount sufficient toprovide the intended degree of coloration of the thermoset resin.

Even though the Cross et al polymeric colorant represents vastimprovement over prior art techniques, certain problems remain withregard to coloration of polyurethane resins, and foams, in particular.During the complex reactions experienced in producing thermosettingresins, such as polyurethane foams, interactions may occur betweencertain substituents of the colorant and reactive components of thereaction mixture. In polyurethane foam production specifically, acareful balance must be maintained throughout the reaction to achievethe desired end product. If the proper balance is not maintained, aproduct may be produced that is outside the desired productspecifications and/or the final product may exhibit poor stability undercertain conditions.

Other approaches to coloration of polyurethanes specifically are setforth in U.S. Pat. Nos. 3,994,835 to Wolf et al and 4,132,840 to Hugl etal. Wolf et al discloses the addition of dispersions of dyestuffscontaining at least one free amino or hydroxyl group capable of reactingwith the isocyanate under the conditions of polyaddition and liquids inwhich the dyes are soluble to an extent less than 2 percent. Hugl et aldisclose the coloration of polyurethane resins with dyestuffs having theformula ##STR2## wherein R₁ is hydrogen, halogen, optionally substitutedC₁ -C₄ alkyl, optionally substituted C₁ -C₄ alkoxy and optionallysubstituted C₁ -C₄ alkylcarbonylamino and R₂ denotes hydrogen,optionally substituted C₁ -C₄ alkyl and optionally substituted C₁ -C₄alkoxy, while A and B denote optionally branched alkylene chains whichcan be identical or different and preferably have 2 to 6 carbon atoms.

Also as noted in "New Uses For Highly Miscible Liquid PolymericColorants In The Manufacture of Colored Urethane Systems", a paperpresented by P. D. Moore, J. W. Miley and S. Bates at the 27th AnnualTechnical/Marketing Conference for SPI, many extra advantages areattendant to the use of polymeric colorants in polyurethanes beyond themere aesthetic coloration of same. Specifically, such polymericcolorants can act as important process control indicators which enableone to more closely maintain quality control parameters by visualobservation of product color. While the polymeric colorants of Moore etal are of the type referred to in the aforementioned Cross et al patent,like advantages may also be realized from reactive colorants accordingto the present invention. In fact, certain of the Cross et al colorantsencounter adverse interactions in the production of polyurethane foamwhich are not encountered by the novel colorants of the presentinvention. Particularly, it has been determined that while all of theCross et al polymeric colorants may be successfully employed in thecoloration of thermoset resins generally, certain of the colorants failin the production of polyurethane foams where tin catalysts and flameretardant chemicals are present.

Certain known prior art discloses dyestuffs that are somewhat related tocertain of the colorants of the present invention, e.g. U.S. Pat. Nos.2,827,450; 4,301,068; 4,113,721; 4,282,144; 4,301,069; 4,255,326;British Patents 1,583,377; and 1,394,365; and German Offenlegungscrift2,334,169. Likewise the above prior art discloses techniques forcoloration of polyurethane resins. None of the known prior art, however,teaches or suggests the use of thiophene based, reactive colorants forin situ coloration as taught and claimed herein.

A need, therefore, continues to exist for a coloring agent which hasexcellent water resistance, oil resistance and/or bleeding resistance,and which at the same time may be easily incorporated into the reactionmixture without adverse interaction with components of the reactionmixture. Accordingly, it would be highly desirable to provide a processfor preparing colored thermosetting resin products in which the coloringagent has the foregoing advantages. Briefly, the present invention isdirected to reactive colorants which combine the very desirablecharacteristics of high color yields of dyes with the non-migratoryproperties of pigments. The result is a product which is superior toboth dyes and pigments in terms of cost effectiveness and properties ofthe cured polymer system.

According to the present invention novel reactive colorants are providedof the formula: ##STR3## wherein R₁, R2 and R3 are selected fromhalogen, carboxylic acid, alkanoyl, aryloyl, carbocyclic formingpolymethylene chains, alkyl, aryl, cyano, thioalkyl, dithioalkyl,thioaryl, dithioaryl, thiocyano, carboxyalkyl, carboxyaryl, amidoalkyl,amidodialkyl, amidoaryl, amidodiaryl, oxyalkyl, oxyaryl, thioamidoalkyl,thioamidodialkyl, or hydrogen when an adjacent group is isobutyryl; R₄,R₅, R₆ and R₇ b are selected from hydrogen, alkyl, oxyalkyl, oxyaryl,sulfonamidoalkyl, sulfonamidoaryl, amidoalkyl, amidodialkyl, amidoaryl,amidodiaryl, halogen, thioalkyl and thioaryl; and R₈ and R₉ are selectedfrom polyalkylene oxide, coppolymers of polyalkylene oxides, andhydroxyalkylenes.

According to a preferred embodiment the R₁, R₂ and R₃ groups in theabove formula may be selected from cyano lower alkyl, a carbocyclicforming polymethylene chain, carboxyalkyl, alkanoyl, amidoaryl orhydrogen when an adjacent group is isobutyryl. In an even more preferredembodiment, the R₄, R₅ and R₆ groups in the above formula may beselected from hydrogen, halogen or lower alkyl.

Colorants according to the present invention are generally liquid atambient conditions of temperature and pressure, though if not, aregenerally soluble in reactants of processes in which they are employed.

In order to avoid adverse interactions during production of thepolyurethane resin, the presence on the thiophene ring of certainsubstituents such as NO₂, NO, NH₂, NHR (where R is alkyl or aryl), SH,OH, CONH₂, SO₂ NH₂ as well as hydrogen except as specified above shouldbe avoided.

The substituents provided in the R₈ and R₉ position for colorants of thepresent invention may be any suitable substituent having two or morecarbon atoms and which will accomplish the objects of the presentinvention. Typical of such substituents which may be attached to thedyestuff radical are the hydroxyalkylenes, polymeric epoxides, such asthe polyalkylene oxides and copolymers thereof. Polymeric substituentsare preferred. In this regard, polyalkylene oxides and copolymers ofsame which may be employed to provide the colorant of the presentinvention are, without limitation, polyethylene oxides, polypropyleneoxides, polybutylene oxides, copolymers of polyethylene oxides,polypropylene oxides and polybutylene oxides, and other copolymersincluding block copolymers, in which a majority of the polymericsubstituent is polyethylene oxide, polypropylene oxide and/orpolybutylene oxide. Further, such substituents generally have an averagemolecular weight in the range of from about 44 to about 2500, preferablyfrom about 88 to about 1400, but should not be so limited.

Examples of particularly preferred compounds within the scope of thepresent invention are set forth below (in each instance R₈ and R₉ areselected from a copolymer of ethylene oxide and propylene oxide having amolecular weight of from about 88 to about 1400). ##STR4##

In formulas 1 through 10, R8 and R9 have the values given above. Anysuitable procedure may be employed to produce the reactive colorants ofthe present invention whereby the reactive substituent, or substituents,are coupled to an organic dyestuff radical. For example, the procedureset forth in U.S. Patent 3,157,633, incorporated herein by reference,may be employed.

Further, it may be desirable to use an organic solvent as the reactionmedium since the reactive substituent is preferably in solution whencoupled to the organic dyestuff radical. Any suitable organic solution,even an aqueous organic solution, may be employed. The particular shadeof the colorant will depend primarily upon the particular dyestuffradical selected.

A large variety of colors and shades may be obtained by blending two ormore colorants. Blending of the colorants of the present invention canbe readily accomplished as the colorants are preferably liquid, thoughif not, have substantially identical solubility characteristics.Therefore, the reactive colorants are in general soluble in one another,and are also in general completely compatible with each other.

For example, the colorants according to the present invention may beprepared by converting a dyestuff intermediate containing a primaryamino group into the corresponding reactive compound, and employing thereactive compound to produce a colored product having a chromophoricgroup in the molecule. In the case of azo dyestuffs, this may beaccomplished by reacting a primary aromatic amine with an appropriateamount of an alkylene oxide or mixtures of alkylene oxides, such asethylene oxide, propylene oxide, or even butylene oxide, according toprocedures well known in the art.

Once the reactive coupler is produced along the lines described above,same can be reacted with the thiophene derivative as set forth in theExamples one through five hereinafter. As can be seen from the Examples,the colorant form includes liquids, oils, and powders, all of which maybe successfully employed in a coloration process.

Reactive colorants of the invention may be incorporated into a resin forcoloration of same by simply adding the colorant to the reaction mixtureor to one of the components of the reaction mixture before or during thepolyaddition reaction. For instance, for coloration of polyurethaneresin, the colorant may be added to the polyol or even in some instancesto the polyisocyanate component of the reaction mixture either before orduring polyurethane formation. The subsequent reaction may be carriedout in the usual manner, i.e, in the same way as for polyurethane resinswhich are not colored.

The products of the present invention are advantageous for use in theproduction of polyurethane foams in which several reactions generallytake place. First an isocyanate such as toluene diisocyanate is reactedwith a polyol such as polypropylene glycol in the presence of heat andsuitable catalyst. If both the isocyanate and the polyol aredifunctional, a linear polyurethane results, whereas should either havefunctionalities greater than two, a cross linked polymer will result. Ifthe hydroxylic compound available to react with the --NCO group iswater, the initial reaction product is a carbamic acid which is unstableand breaks down into a primary amine and carbon dioxide. Since excessisocyanate is typically present, the reaction of the isocyanate with theamine generated by decarboxylation of the carbamic acid occurs, and ifcontrolled, the liberated carbon dioxide becomes the blowing agent forproduction of the foam. Further, the primary amine produced reacts withfurther isocyanate to yield a substituted urea which affords strengthand increased firmness characteristics to the polymer.

In general, amine and tin catalysts are used to delicately balance thereaction of isocyanate with water, the blowing reaction, and thereaction of isocyanate with polymer building substituents. If the carbondioxide is released too early, the polymer has no strength and the foamcollapses. If polymer formation advances to rapidly a closed cell foamresults which will collapse on cooling. If the colorant or anothercomponent reacts to upset the catalyst balance poorly formed foam willresult.

Additionally, the substituted urea may react with excess isocyanate, andthe urethane itself reacts with further isocyanate to cross-link thepolymer by both biuret and allophonate formation. Foams colored by thepresent colorants may be soft, semi-rigid, or rigid foams, including theso-called polyurethane integral skin and microcellular foams.

Coloring agents according to the present invention are reactive coloringagents, and may be added to the reaction mixture, or to one of thecomponents thereof. When in liquid form, colorants of the presentinvention may be added as one or more of the components of the reactionmixture. Conversely when in oil or powder forms, the colorants are firstadded to one of the reactive components and are carried thereby, orconversely are dissolved in a solvent carrier and added as a separatecomponent. Obviously liquids have significant processing advantages oversolids, and may, if desired, be added directly to the reaction mixtureso that no extraneous nonreactive solvent or dispersing agent ispresent.

Polyurethane products which may be colored with reactive colorants ofthe present invention are useful for producing shaped products byinjection molding, extrusion or calendering and may be obtained byadding the coloring agent to the polyol or diol component of thereaction mixture, or to one of the other components, although additionto the polyol component is preferred. The polyols may be polyesterswhich contain hydroxyl groups, in particular reaction products ofdihydric alcohols and dibasic carboxylic acids, or polyethers whichcontain hydroxyl groups, in particular products of the addition ofethylene oxide, propylene oxide, styrene oxide or epichlorohydrin towater, alcohols or amines, preferably dialcohols. The coloring agent mayalso be admixed with the so-called chain extending diols, e.g., ethyleneglycol, diethylene glycol and butane diol. In general, it is desirablenot to use more than about 20 percent by weight of coloring agent basedon the weight of polyol. In most cases very strong colorations areproduced with a small proportion of the coloring agent. For example,from about 0.1 to about 5 percent, preferably 0.5 to 2 percent by weightcoloring agent may be utilized based on the weight of polyol.

The preferred colorants of the invention may be soluble, for instance,in most polyols which would be used in polyurethanes, and in themselves.This property may be particularly valuable for three reasons. First,this solubility may permit rapid mixing and homogenoeous distributionthroughout the resin, thus eliminating shading differences and streakswhen properly mixed. Second, the colorant may have no tendency to settleas would be the case with pigment dispersions. Third, it is possible toprepare a blend of two or more colors which provides a wide range ofcolor availability.

Present reactive coloring agents may also be of considerable value inreaction injection molding (RIM) applications. The RIM process is amethod of producing molded urethanes and other polymers wherein the tworeactive streams are mixed while being poured into a mold. Uponreaction, the polymer is "blown" by chemicals to produce a foamedstructure. This process may be hindered by the presence of solidparticles, such as pigments. The present invention may not cause thishindrance because there are no particles in the system and the colorantbecomes part of the polymer through reaction with one of the components.

The following examples illustrate the invention, and parts andpercentages, unless otherwise noted are by weight:

EXAMPLE 1

Ninety two and one half grams of phosphoric acid (85% strength) wasadded along with 12.5 grams of sulfuric acid (98% strength) and 2 dropsof 2-ethylhexanol defoamer to a 500 ml closed flask. The mixture wasthen cooled and 8.2 grams of 2-amino-3,5-dicyano-4-methyl thiophene wasadded followed by further cooling to below 0° C. Eighteen grams ofnitrosyl sulfuric acid (40%) was slowly added while maintainingtemperature below 0° C. After three hours, the mixture was tested fornitrite. A positive nitrite test was obtained and one gram of sulfamicacid was added and a vacuum was pulled. After one hour, a negativenitrite test was obtained. Ten and eight tenths grams of coupler(M-toluidine--2EO), 300 grams of ice and water, and 2 grams of urea wereadded to a 4 liter beaker and cooled to below 0° C. The diazo solutionfrom the flask was added dropwise to the beaker over 40 minutes,maintaining temperature below 0° C. The resulting mixture was stirredfor several hours and allowed to stand overnight, after which 122 gramsof sodium hydroxide (50%) were added to neutralize excess acid to a pHof about 7. The resulting product was filtered, washed several timeswith hot water. It was then dissolved in isopropyl alcohol, andprecipitated again by adding water, filtered and dried to give a violetpowder that melted at 208° C.

EXAMPLE 2

The procedure of Example 1 was followed with the exception of amounts ofreactants and the particular thiophene and coupler employed, all ofwhich are specified

49 ml--acetic acid

19.5 ml--propionic acid

2.5 grams--H2S04

1 drop--2-ethylhexanol defoamer

5.7 grams--2-amino-3-carbomethoxy-5-isobutyryl thiophene

9 grams--nitrosyl sufuric acid

0.5 grams--Sulfamic acid

4.5 grams--2-methoxy-5-acetamido-aniline 2EO

100 grams--ice

2 grams--urea

50 grams--ammonium acetate

300 grams--water and ice

The precipitated product (after neutralizing with sodium hydroxide) wascollected and water washed several times. The product was oven dried at75° C. and give a bluish violet solid.

EXAMPLE 3

The procedure of Example 1 was followed except for amounts of reactantsand the particular thiophene and coupler. Such are set forth below asfollows:

200 grams--H₃ PO₄

25 grams--H₂ SO₄

2 drops--2-ethylhexanol defoamer

16.3 grams--2-amino-3,5-dicyano-4-methyl thiophene

35 grams--nitrosyl sulfuric acid

3 grams--sulfamic acid

121 grams--m-toluidine-2EO/15PO/2EO

60.5 grams--ice

4 grams--urea

The excess acid was neutralized with 272 grams of 50% sodium hydroxide,the bottom salt layer of the reaction mixture was removed hot and theproduct was dissolved in methylene chloride, washed four times and thendried over magnesium sulfate. The methylene chloride solution was thenfiltered and stripped to yield a violet oil.

EXAMPLE 4

The procedure of Example 3 was followed with the exception of amount ofreactants and the particular thiophene and coupler employed, all ofwhich are specified

183 Grams--H₃ PO₄

25 grams--H₂ SO₄

2 drops--2-ethylhexanol defoamer

25.7 grams--2-amino 3,5-dicarboethoxy -4-methyl thiophene

35 grams--nitrosyl sulfuric

1 gram--sulfamic acid

121 grams--m-toluidine 2EO/15PO/2EO

247 grams--ice

2 grams--urea

A red oil resulted.

EXAMPLE 5

The procedure of Example 3 was followed with the exception of amount ofreactants and the particular thiophene and coupler employed, all ofwhich are specified below:

100 grams--H₃ PO₄

15 grams--H₂ SO₄

2 drops--2-ethylhexanol defoamer

8.9 grams--2-amino-3-cyano-4,5tetramethylene thiophene

17.5 grams--nitrosyl sulfuric

1 gram--sulfamic acid

60.5 grams--m-toluidine 2EO/15PO/2EO

120 grams--ice

A red oil resulted.

EXAMPLE 6

A masterbatch for the production of polyurethane foam was prepared byadding 3000 grams of Niax-16-56 (a 3000 molecular weight triol availablefrom Union Carbide) 125.1 grams of water, and 7.8 grams of Dabco 33LV(amine catalyst available from Air Products) to a one gallon plasticjug, mixed well and stored at 65oF for further use.

EXAMPLE 7

A polyether polyurethane foam (control) was produced as follows. Onehundred and four grams of the masterbatch of Example 6 were added to a400 milliliter disposable beaker, and one gram of a reactive colorant astaught herein was added thereto along with one milliliter of LiquidSilicone L-520 (available from Union Carbide). The mixture was stirredin a blender for 25-30 seconds, 0.20 milliliters of T-9 (stannousoctanoate catalyst) added thereto from a syringe, and stirred for anadditional 5-8 seconds. Thereafter, 46 milliliters of toluenediisocyanate were added to the beaker and the mixture stirred for sixseconds. A blended, homogenous mixture resulted and was poured into an83 ounce paper bucket. The mixture foamed, and after the foam stoppedrising, was cured in an oven at 130° C. for 15 minutes.

EXAMPLE 8

Polyurethane foam samples containing a flame retardant were produced asdescribed in Example 7 with the exception that 10 grams of ThermolinT-101 flame retardant (available from Olin) were added to the beakerwith the other components, and the foam sample was cured at 130° C. for30 minutes. The foam of this Example possessed flame retardantproperties.

As discussed above, while a number of colorants have heretofore beenutilized for in situ coloration of polymeric materials, polyurethanefoams present somewhat special problems. Specifically, the colorant mustbe stable to tin catalysts utilized in the production of the urethane,and also stable to flame retardants that are normally included in thepolymer.

Instability as to the stannous tin catalysts, results in reduction ofthe dyestuff leading to significant, if not total, loss of color.Additionally, the foam producing process is also adversely affected. Thefoam does not rise at a proper rate and does not cure at a fast enoughrate. A tacky polyurethane with poor polymer properties results. It isthus important that colorants for polyurethanes be stable to the tincatalysts. This is a desirable and qualifying characteristic ofcolorants of the present invention.

Also with instability to flame retardants, a color change or color shiftwill appear which renders an unstable colorant useless. Typicallycolorants unstable to flame retardants change color as follows: red toviolet and orange to red. While a number of commercially availabledyestuffs are not stable in the presence of the flame retardants,colorants of the present invention do possess such stability.

In order to demonstrate stability to both the tin catalysts and flameretardants, Examples 7 and 8 were reproduced with a number of differentspecific colorants, both according to the present invention andotherwise. Example 7 (without flame retardant) serves as a control forevaluation of stability to flame retardants. The tin stability test isset forth in Example 9.

EXAMPLE 9

Tests were also conducted as to tin stability according to the followingprocedure. First the color value for the colorants tested was determinedby placing about 0.10 to 0.15 grams of colorant into a 100 millilitervolumetric flask and adding approximately 40 to 50 milliliters ofmethanol. The flask was swirled until the colorant dissolved in themethanol, after which excess methanol was added to the 100 millilitermark on the flask. The flask was stoppered and the contents were mixedand shaken. Exactly 2.0 milliliters of the solution of the colorant inmethanol was then added to a separate like flask and the flask wasfilled with methanol to the 100 milliliter mark, stoppered and shaken.

A Beckman DU-7 spectrometer was zeroed with methanol, filled with thetest solution, and the solution was scanned from 300 to 750 mm. Themaximum absorbance was recorded. Color value is obtained by multiplyingthe sample weight by 0.2 and dividing the product obtained into themaximum absorbance value.

In the case of liquid phase colorant, the colorant to be tested was thenadded to a 50 milliliter volumetric flask.

In order to correct for varying color strengths the amount of colorantadded was determined by the following formula:

    5/(Color value)=number of grams added.

Then 35 milliliters of 2-ethoxyethylether or 2-methoxylethylether wereadded to dissolve the colorant. Further solvent was then added to bringthe total contents to the 50 milliliter mark. The flask was stopperedand shaken. Exactly 2.0 milliliters of this solution were transferred toa further 50 milliliter flask and diluted to the 50 milliliter mark withone of the solvents.

In the case of solid colorant to be tested colorant to be tested wasadded to a 100 ml volumetric flask. In order to correct for varyingcolor strengths the amount of colorant added was determined as follows:

    5/2 (color value)=number of grams added.

Then 35 ml of 2-ethoxyethyl-either or 2-methoxyethylether solvent wasadded to dissolve the colorant. An additional amount of solvent wasadded to bring the level in the volumetric flask to the 100 ml mark; astopper was inserted, and the contents of the flask were mixed well byshaking. Exactly 4.0 ml of this solution were then transferred toanother 100 ml volumetric flask and diluted to the 100 ml mark withsolvent.

A solution of T-9 (stannous octanoate) was prepared with minimum airexposure by dissolving 0.70 gram of stannous octanoate in sevenmilliliters of solvent in a vial which was kept sealed between runs. TheBeckman spectrometer was set up for repetitive scanning. Two millilitersof colorant solution (either solid or liquid as described above) wereplaced into a vial with 2.0 milliliters of the tin catalyst solution andmixed well. The mixture was then transferred to the cell of thespectrometer which was capped and quickly placed into the spectrometer(not more than 20 to 30 seconds elapsed time). Five repetetive scanswere then made for each colorant sample at three intervals. Thepercentage loss after fifteen minutes (5 scans) was measured frominitial absorbance and last absorbance.

A number of commercially useful benzothiazole colorants wereinvestigated as to stability to flame retardants. In the control test,i.e., no flame retardant present, following the procedures of Example 7,all of the compounds tested passed, indicating no color change. When,however, the same compounds were included in production of foamaccording to Example 8 where the flame retardant was included, all ofthe compounds failed.

EXAMPLE 10

In like fashion to the benzothiazole investigations, a number ofcolorants according to the present invention were prepared according tothe general procedures set forth in Examples 1 through 5. Thereafter,the colorants were utilized in the coloration of polyurethane foams asdescribed in Examples 7 and 8 to determine stability of same to flameretardants. All of the thiophene compounds passed both tests, indicatingstability to flame retardants. Compounds tested are listed in Table Ibelow.

The following abbreviations are utilized in the following tables:Et=ethyl; EO=ethylene oxide; PO=propylene oxide; ME=methyl; Ac=acetate.Also where numbers are separated by diagonals, eg. 2/15/5, such refersto moles EO/moles PO/moles EO.

                                      TABLE I                                     __________________________________________________________________________    Effect of Flame Retardants on Thiophene Reactive Colorants                     ##STR5##                                                                     Ex.                                                                           No.                                                                              R.sub.1 R.sub.2                                                                          R.sub.3                                                                              R.sub.4                                                                           R.sub.7                                                                          R.sub.8, R.sub.9                                                                       Color                                    __________________________________________________________________________    11 CO.sub.2 Et                                                                           Me CN     H   H  2EO/15PO/5EO                                                                           Red                                      12 "       "  "      Me  "  "        Red                                      13 "       "  "      OMe OMe                                                                              2/10/5   Violet                                   14 "       "  COMe   H   H  2/15/5   Red                                      15 CN      "  CO.sub.2 Me                                                                          "   "  "        Red                                      16 CO.sub.2 Et                                                                           "  CONHC.sub.6 H.sub.5                                                                  "   "  "        Red                                      17 "       "  "      Me  "  2/15/5   Red                                      18 "       "  "      H   "  "        Red                                      19 "       "  CO.sub.2 Et                                                                          "   "  "        Red                                      20 "       "  "      Cl  "  2/10/6   Red                                      21 "       "  "      Me  "  2/15/2   Red                                      22 CO.sub.2 Me                                                                           "  CO.sub.2 Me                                                                          H   "  2/15/5   Red                                      23 "       "  "      "   "  2/10/6   Red                                      24 CO.sub.2 Et                                                                           "  CO.sub.2 Et                                                                          "   "  2/15/5   Red                                      25 "       "  "      Cl  "  "        Red                                      26 CO.sub.2 Me                                                                           "  CO.sub.2 Me                                                                          "   "  "        Red                                      27 "       "  CO.sub.2 Et                                                                          H   "  2/10/6   Red                                      28 CN      "  CN     OMe OMe                                                                              2/10/5   Violet                                   29 "       "  "      Me  H  2/15/5   Violet                                   30 "       "  "      "   "  2/15/2   Violet                                   31 "       "  "      "   "  2/10/8   Violet                                   32 "       "  "      "   "  2/7/6    Violet                                   33 "       "  "      "   "  2/10/6   Violet                                   34 "       "  "      H   "  2/15/5   Violet                                   35 CN      "  CN     Me  H  2EO      Violet                                   36 "       "  "      OMe OMe                                                                              "        Blue                                     37 "       "  "      NHAc                                                                              OMe                                                                              "        Blue                                     38 "       (CH.sub.2).sub.4                                                                        H   H  "        Red                                      39 CO.sub.2 Et                                                                           Me CO.sub.2 Et                                                                          "   "  "        Red                                      40 CO.sub.2 Me                                                                           H  COCHMe.sub.2                                                                         NHAc                                                                              OMe                                                                              "        Violet                                   41 CO.sub.2 Et                                                                           (CH.sub.2).sub.4                                                                        Me  H  2/15/2   Red                                      42 "       (CH.sub.2).sub.4                                                                        H   "  2/15/5   Red                                      43 "       "         Me  "  2/15/8   Red                                      44 "       "         H   "  2/10/6   Red                                      45 "       "         Me  "  2/15/8   Red                                      46 CO.sub.2 Et                                                                           "         H   H  2/15/5   Red                                      47 CO.sub.2 Me                                                                           H  COCHMe.sub.2                                                                         Me  H  2/15/2   Violet                                   48 CONHC.sub.2 H.sub. 4 OH                                                               "  "      "   "  "        Blue                                     49 CO.sub.2 Me                                                                           "  "      OMe "  2/10/5   Violet                                   50 CONHC.sub.2 H.sub.4 OH                                                                "  "      "   OMe                                                                              "        Blue                                     51 "       "  "      NHAc                                                                              "  "        Blue                                     __________________________________________________________________________

Benzothiazoles of the type tested as to flame retardant stability werealso tested as to stability as to the stannous octanoate catalystaccording to the test procedures set forth in Example 9. Compounds andresults are set forth in Table II.

                  TABLE II                                                        ______________________________________                                        Effect of Stannous Octonate Catalyst on Colorants                             For Polymeric Resins                                                           ##STR6##                                                                     Ex.                                                                           No.   R.sub.1                                                                              R.sub.2                                                                              R.sub.3                                                                            R.sub.4                                                                              R.sub.8, R,.sub.9                                                                   % Loss Color                            ______________________________________                                        52    H      H      OMe  Me     10EO  56.5   Red                              53    Cl     "      H    H      2/15/5                                                                              91.5   Red                              54    OMe    "      "    OMe    12EO  66.7   Red                              55    Me     "      Cl   H      2/10/5                                                                              85.9   Red                              56    Cl     "      H    Cl     2/15/5                                                                              97.8   Red                              57    "      "      Cl   H      "     87.9   Red                              58    H      Cl     "    "      "     100.0  Red                              ______________________________________                                    

Like tests were performed as to colorants according to the presentinvention, results of which may be compared to the benzothiazole resultsof Examples 52 through 58. Compounds tested and results are set forth inTable III.

                                      TABLE III                                   __________________________________________________________________________    Effect of Stannous Octoate on Thiophene Based Colorants                        ##STR7##                                                                     Ex.                                                                           No.                                                                              R.sub.1                                                                           R.sub.2                                                                           R.sub.3                                                                              R.sub.4                                                                           R.sub.7                                                                           R.sub.8, R.sub.9                                                                  % Loss                                                                            Color                                       __________________________________________________________________________    59 CO.sub.2 Et                                                                       Me  CO.sub.2 Et                                                                          Me  H   2/15/2                                                                            5.3 Red                                         60 CN  "   CN     H   "   2/15/5                                                                            0.0 Violet                                      61 CO.sub.2 Et                                                                       "   "      "   "   "   3.3 Red                                         62 CN  "   CO.sub.2 Et                                                                          "   "   2/15/8                                                                            2.9 Red                                         63 CO.sub.2 Et                                                                       "   "      Cl  "   2/10/6                                                                            2.7 Red                                         64 CN  "   CN     OMe OMe "   6.2 Blue                                        65 CO.sub.2 Et                                                                       "   "      CN  H   2/15/2                                                                            4.0 Red                                         66 CN  "   CO.sub.2 Et                                                                          H   "   2/15/5                                                                            5.9 Violet                                      67 CO.sub.2 Et                                                                       "   COMe   "   "   "   4.8 Red                                         68 "   "   CONHC.sub.6 H.sub.5                                                                  Me  "   2/15/2                                                                            3.0 Red                                         69 CN  "   CN     OMe "   12EO                                                                              7.0 Violet                                      70 CN  (CH.sub.2).sub.4                                                                         H   H   "   3.2 Red                                         71 "   "          Me  "   2/15/8                                                                            2.3 Red                                         72 "   "          H   "   2/15/5                                                                            0.9 Red                                         73 CN  Me  CN     Me  H   2EO 3.9 Violet                                      74 "   "   "      OMe OMe "   4.2 Blue                                        75 "   "   "      NHAc                                                                              "   "   4.4 Blue                                        76 "   (CH.sub.2).sub.4                                                                         H   H   "   2.1 Red                                         77 CO.sub.2 Et                                                                       Me  CO.sub.2 Et                                                                          "   "   "   5.6 Red                                         78 "   H   COCHMe.sub.2                                                                         NHAc                                                                              OMe "   4.8 Blue                                        __________________________________________________________________________

As can be seen from a comparison of the benzothiazoles of Examples 52 to58 and the thiophenes of Examples 59 to 78, only the thiophenes arestable to the effects of the tin catalyst. Moreover, as defined herein,all of the thiophenes exhibit similar stability.

Having described the present invention in detail it is obvious that oneskilled in the art will be able to make variations and modificationsthereto without departing from the scope of the present invention.Accordingly, the scope of the present invention should be determinedonly by the claims appended hereto.

That which is claimed is:
 1. A coloring agent, having the formula:##STR8## wherein R₁, R₂ and R₃ are selected from halogen, carboxylicacid, alkanoyl, aryloyl, carbocyclic forming polymethylene chains,alkyl, aryl, cyano, thioalkyl, dithioalkyl, thioaryl, dithioaryl,thiocyano, carboxyalkyl, carboxyaryl, amidoalkyl, amidodialkyl,amidoaryl, amidodiaryl, oxyalkyl, thioamidoalkyl, thioamidodialkyl, orhydrogen when an adjacent group is isobutyryl; R₄, R₅, R₆ and R₇ areselected from hydrogen, alkyl, oxyalkyl, oxyaryl, sulfonamidoalkyl,sulfonamidoaryl, amidoalkyl, amidodialkyl, amidoaryl, amidodiaryl,halogen, thioalkyl and thioaryl; and R₈ and R₉ are polyalkylene oxideshaving an average molecular weight of from about 44 to about 2500selected from polyethylene oxide, polypropylene oxide, polybutyleneoxide and copolymers of polyethylene oxide, polypropylene oxide andpolybutylene oxide.
 2. The coloring agent of claim 1, wherein R₁, R₂,and R₃ are selected from cyano, lower alkyl, a carbocyclic formingpolymethylene chain, carboxyalkyl, alkanoyl, amidoaryl or hydrogen whenan adjacent group is isobutyryl.
 3. The coloring agent of claim 2wherein R₄, R₅, R₆ and R₇ are selected from hydrogen, halogen or loweralkyl.
 4. A coloring agent of the formula: ##STR9## wherein R₈ and R₉are selected from polyalkylene oxide and copolymers of polyalkyleneoxides having an average molecular weight of from about 88 to about1400.